In recent years, a number of platinum (II) complexes, including well-known cisplatin, have been synthetized and have been reported to have antitumor activity. We the present inventors, have synthetized some platinum (II) complexes, as disclosed, for example, in Japanese Patent Application First Publn.(KOKAI) Nos. 31648/78, 35013/80, 130992/80, 103192/81, 156416/82, 16895/82, 21697/84, 34982/85, 34983/85, 97991/85, 109521/85, Japanese Patent Application Second Publn. (KOKOKU) No. 29957/83 and Japanese Patent Application No. 196887/85, as well as U.S. Pat. Nos. 4,169,846; 4,200,583; 4,256,652; 4,255,347; 4,551,524 and U.S. patent application Ser. No. 637,463 and European Patent Nos. 1126 and 8936, European Patent Appln. Nos. 83 303659.3 and 84 305304.2.
We have also synthetized some organoplatinum (IV) complexes, as disclosed, for example, in Japanese Patent Application First Publication (KOKAI) Nos. 87295/85 and 109521/85.
Meanwhile, it is always demanded that new, anti-tumor platinum complexes having any more excellent properties than the known antitumor organoplatinum complexes are created and provided for uses in therapeutic treatment of tumors.